Storage battery for hearing-aids



Nov. 7, 1939. G. WHEAT STORAGE BATTERY FOR HEARING-AIDS /N-VENTOR FiledSept.` 27, 1955 g: ATTORNX er er' Patented Nov. 7A, 1939 Grant Wheat,

Marlboro,

Mass., assigner to Koehler Manufacturing Company, Marlboro, Mass., acorporation of Massachusetts Application September 27, 1935, Serial No.42,477

4 Claims.

This invention relates to apparatus designed for use by deaf persons toaid them in hearing. The most eifective type of suchvapparatus operateson the telephone principle and conse-` pared to a chemical dry cell, canbel made availl ablefor these purposes.

In order to satisfy these requirements, the storage battery must besmall enough to be car- Tied conveniently in the pocket, must be verylight in weight, strong enough to withstand an occasional accidentaldropping, easy to fill and charge, and above all, must be proof againstleakage and corrosion. To devise a battery that will fulfill theserequirements constitutes the chief object of this invention. f

, The nature of the invention will be readily understoodfrom thefollowing description when read in connection with the accompanyingdrawing, and the novel features will be particularly pointed out in theappended'claims.

In the drawing:

Figure 1 is a perspective view of a portion of a storage battery and anamplifier combined;

Fig. 2 is a view, partly in side elevation and partly in verticalsection, of the battery illustrated in Fig, 1;

, Fig. 3 is a sectional view through the closure and cover of thebattery on approximately the line 3 3, Fig. 2;

Fig. 4 is a plan view of the battery withthe cover removed;

Fig. 5 is a view of the"`cover in an inverted position;

t e battery shown in Fig. 2;

lFigs. '7 and 8 are side views of the lower portions of different formsofseparators that can be used in the battery; and

Fig. 9 is a transverse, sectional view of a slightly different form ofbattery.

-The battery shown comprises'a jar 2 which may be made of Bakelite,vulcanite, or any other suitable material having the necessaryinsulating properties and adapted to be molded into the desired form. Itis-relatively thin and -flat and of such dimensions as to convenientlyiit in a vest pocket. vIn the particular form shown two cham- 55 bersare provided to receive the battery elements,

' in my prior patents, except for the matter of di- Fig. 6 is atransverse, vertical, sectional view of (Cl. 13G-170) thus providing twocells, as indicated at 3 and l, respectively, Fig. 4, these cellsvbeingvseparated by a partition 5. The upperends of the csi; are closed by softrubber gaskets or closures i and 1, 4iitting tightly into the ends ofthe charu-V 5 bers, and the leads for the plates' are led through thesegaskets. So` far as these features are concerned the construction issimilar to those shown mensions. a 10 This battery also includes a cover8 which is removably secured to the jar 2 'and forms a convenientsupport for the amplifier ill to which the transmitter (not shown)andthe receiver I2 of the hearing-aid are connected. Preferably l5 theparts that secure the amplifler, cover and jar together mechanically arealso utilized to connect these elements electrically.

For this purpose screw threaded terminal binding posts I 3 and I4, Fig.'4, are molded or other- 20 wise secured in the wall'of the jar andproject above its top at opposite ends thereof. They are adapted toextend through holes I5 and I6, respectively, Fig. 5, in the cover 8,and to receive insulated thumb nuts l1 and i8 by means of 25 which thecover is secured to the jar. Preferably both studs I3 and Il are oisetlaterally fr'om the center line of the jar, as shown in Fig. 4, and theholes are correspondingly placed so that Iit is impossible to make thecover t properly on the jar except in one position. Also, the lowermargin of the cover is grooved, as shown at 20. and the top of the jaris correspondingly v.shouldered to facilitate the centering of the coveron the jar. The leads from the plates of the two cells are connectedtogether by the intermediate member 2l, Figs. 2 and 4, and the otherterminals are connected 'by bars or straps 22 and 23, Fig. 4, to therespective posts l! and Il, so that these posts form the electricalterminals of the battery.

The connection between the terminal I4 and the amplifier in includes aspecial connector 24, Figs. 2, 3 and 5. It is made of sheet metal, suchas copper or lbrass, is bent to the peculiar shape shown, and includes abottom plate to which the lower end of the core a for the nut Il isattached by a loose connection which prevents I the separation of thesemembers but permitsthe part a to rotate in the extension of the bracket.The insulating cap b for the nut Il is molded on to the core a. Theconnector extends into an aperture or cavity formed in the cover I, andis provided with a turned-over edge portion 25 that is cut out, as shownin Fig. 5, to receive the terminal stud :s which is gigio with, andprojects 5s' downwardly from, the amplier I0. Projecting laterally intothe cover isa screw 21, the inner end of which is threaded into theupright portion of the connector 24, so that by turning this 5 screw up,the part 25 of the connector can be tightened into the grooved portionof the stud 26 and thus will make a good electrical connection with itand also lock it mechanically to the cover'8. The same construction isused at the opposite end of the cover to cooperate with the nut I1 andAstud I3, and these parts are indicated in Figs. 1, 2V and 5 by the same,but primed, numerals.

It will be observed that with this arrangement the amplifier I0 isnormally secured rigidly to the cover 8, and these two parts can bedisconnected, as a unit, from the battery jar by unscrewing the nuts I1and I8. -At the same time these parts can be separated, if desired, bybacking out the screws '2T-21' far enough to release the studs 26'26. Incharging the battery the cap or cover may either be disconnected and thebattery placed on charge, or the terminals of the charging circuit may'be connected to the battery terminals I3 and I4 without removing thecap.

The cell chambers must be vented, and for this purpose vent tubes 28 and28', Figs. 2 and 4, are mounted in the closures 6 and 1, and their upperends are ared out or enlarged for engagement 30 with a pad 30 ofabsorbent brous material. This pad may conveniently consist of a layerof felt or of several sheets of blotting paper, superposed one uponanother, and tting tightly into the recess 3|, Fig. 5, in the lower sideof the cap or cover 8. The pad should be suiciently thick to tightlyclose the upper ends of the vent tubes when the cap is in place. Itprovides the necessary escape for gas or vapor created in the battery,but absorbs any moisture or acid that may ind its way through the venttube. Preferaby practically all of the electrolyte in the battery isheld in an absorbed condition so that the total quantity of freesolution in the battery consists of only a few drops, and the pad 30 ismade sufciently large to be capable of absorbing all of this freesolution. Thus the escape of any acid to the outside of the battery isdefinitely prevented. This arrangement also provides for the convenientfilling of the battery with distilled water to replenish the loss ofliquid due to evaporation; Water for-this purpose can be introducedthrough the vent tubes 28 and 28', and the lower ends of these tubesarelocated so close to the upper ends of the plates in the separators thatoveriilling is prevented. If the padV 30 becomes wet to any substantialdegree it can readily be replaced. y A In this connection it may bepointed out that the connectors 2l and 24' are separated from thechamber in which the pad 30 is located by a transverse partition, andthat the only metal parts exposed to contact with the gas or vaporescaping from the battery are the lead connecting elements 2|, 22 and 23and the leads from'the battery plates. These parts are not likely to beinjured'by such contact.

A unique construction has' devised to Y minimize the danger ofshort-circuiting of the battery plates due to the collection of sedimentin the bottom of the cell. One arrangement provided for this purpose isillustrated in Fig. 9.l Here the jar 2 is provided with shoulders 3l and32-on which the plates 33 and '34 rest. The separator 35 lls the spacesbetween these plates and `extends down to. the bottom of the cell for adistand ce substantially below the (shoulders 3l an Another arrangementis illustrated in Figs. 2,

6, 7 and 8 where the cell 2 is provided with a central wedge-shaped ange36 extending en- 5 tirely across the bottom of the chamber from one edgethereof to the other, and the separator 35' straddles this ange, itslower edges being wedged between the bottoms of the plates and the ange.The separator may either have a saw 10 scarf 31 in its lower end, asshown in Fig. 7, or it may be made in two pieces, as shown in Fig. 8,the lower ends of these pieces being bevelied to iit the opposite sidesof the ilange 36.

In both the arrangement illustrated in Fig. 9 15 and that shown in theother figures just mentioned, it is practically impossible for thesediment to build up to such an extent as to shortcircuit the batteryplates. Also, shedding of particles of solid material by the plates isminimized 20.

by the face to face contact of the separator with the plates and itstight iit with them at its lower margins. l

While any suitable separating material can be used, I have found that abalsa wood separator 25 made in accordance with the disclosure in mypending application Serial No.26,665, led June 14, 1935, is muchsuperior to any other form of separator, of which I have been able tolearn, in a batterydesigned for the present purposes. It 30 has the highdegree of absorbency necessary to hold an ample body of electrolyte incontact with the plates so that the free iiowing electrolyte is reducedto a minimum, or can be eliminaed altogether; it possesses the necessaryelectrical prop- 35 erties for a good separator, it gives a long periodof service, and is very useful in preventing shedding by the plates.

-In the preferred arrangement, the illling of the battery isaccomplished in the manner shown in 40 Fig. 6,4 since capillaryattraction is liable to cause drops to lodge in the vent tube if it isattempted to pour water into the battery. This diiiculty is overcome byintroducing water with a medicine dropper 38. 'I'he end of the dropperis inserted 45 completely through the vent tube and far enough beyond toreach the spongy wood separator, a hole 39 being provided in the top ofthe separator directly below the vent tube to receive it. The pointof'the medicine dropper enters this hole 50 but preferably does nottouch' the bottom of it.

Water thus is introduced dirctlyinto the separator, and, due to thespongy nature of this member, the water is quickly absorbed until asaturated condition is reached. In this way, 55 water is added to thebatterythrough the vent tube and the air which` it dispiaces is allowedto escape at the same time.

Since the hole in the separator is below the surface of the plates, itacts as a well to collect any free solution which may be in the battery.Also, by using the medicine dropper, the amount of this free solutionmay be determined and any excess maybe removed. 65

While .I have herein shown and described a preferred embodiment of myinvention, it will -be evident thatthe invention may be embodied inother forms without departing from the spirit or scope thereof.

No claim is here made to the novel arrangement or construction of thebattery elements themselves, involving features of the battery l plates,the separator, or the parts which cooperate immediately with them, thesefeatures being cov- 75 ered in a continuing application Ser. No.184,638, filed September 20, 1937.. g

Having thus described my invention, what I desire to claim as new is:

1. A storage -battery comprising a battery jar having a chamber therein,storage battery ele` ments inV said chamber, a cover for said jar,terminals for said batteryl anchored in the wall of said jar, meanscooperating with said terminals to secure said cover removably in itsoperative position on the jar, `a vent tube for said chamber and a bodyof absorbent nbrous material closing the passage through said tube andheid in its operative position by said cover. Y

2. A storage battery comprising a battery jar l having a chambertherein, vstorage battery elements mounted in said chamber, sealingmeans i'orsaid chamber located at the upper end thereoi, a covernormally closing the top of said jarterminal binding posts for securingsaid cover removably in said position on the Jar.

3. A storage battery comprising a battery Alarl having a chamber,therein, storage battery elements mounted in said chamber, sealing meansfor said chamber located at the upper end thereof. a cover normallyclosing the top 'of said lar but removably secured thereon, said coverhaving upper and lower compartments therein and an4 approximately.horizontal partition separating said `601mmrtrnents, connectors locatedin said upper compartment, terminal binding screws'for said batteryextending into the walls of said jar and anchored in said wallsconnected with said elements and projecting through holes in theopposite ends o! said cover, nuts threaded on said screws to clamp saidcover `on said battery jar, and conductorsJ connecting said bindingscrews with said connectors positioned in said upper compartment.

4. A storage battery comprising a battery jar having a chamber therein,storage battery elements mounted in said chamber, sealing means `forsaid chamber located at the upper end thereof, a cover normally clomngthe top otsaid jar but removably secured thereon, said cover having saidcompartments, connectorslocated in-said upper compartments, ahearing-aid amplifier mounted on saidcover and provided with terconnsaid conductors with said connectors above partition, and abody otabsorbent material in, latter compartment serving to,

absorb liquid Aor vapor escaping thereinto from so saidchamber casarwnss'r.

